Pivoted blade lock device



y 2, 1963 E. L. SCHLAGE 3,390,908

PIVOTED BLADE LOCK DEVICE Filed March t 1 y 2, 1968 j E. SCHLAGE3,390,908

PIVOTED BLADE LOCK DEVICE Filed March 4, 1965 5 Sheets-Sheet 2 mvsmon.

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0...] MZWJ lrraaviqy 1968 E. SCHLAGE 3,390,908

Q PIVOTED BLADE LOCK DEVICE Filed March 4, 1965 5 Sheets-Sheet 3mvEN'rOR. izwrsr L. Janus! flrraaviri United States Patent 3,390,908PIVOTED BLADE LOCK DEVICE Ernest L. Schlage, Burlingame, Califi,assignor to Schlage Lock Com any, a corporation Filed Mar. 4, 1965, Ser.No. 437,205 7 Claims. (Cl. 292195) My invention relates to means forholding a door in position in a door frame and is particularly concernedwith such a device especially for use in doors that are quite thin, sothin as not to admit of the installation of the customary commerciallock, and also relates to installations in which the door is able toswing both ways through the door frame on which it is mounted by thecustomary hinges.

An object of the invention is to provide a pivoted blade lock devicewhich can be manufactured in a relatively thin form so that it caneasily be installed within the confines of a thin door.

Another object of the invention is to provide a pivoted blade lockdevice which can be used, although not necessarily so, in connectionwith a door designed and mounted to swing both ways with respect to itsdoor frame.

Another object of the invention is to provide a pivoted blade lockdevice which cannot easily be actuated in an unauthorized fashion.

Another object of the invention is to provide a pivoted blade lockdevice having a deadlatch feature.

An additional object of the invention is to provide a pivoted blade lockdevice that can be utilized effectively with a standard strike device ora special strike device.

Another object of the invention is in general to pro vide an improvedlock device.

Other objects together with the foregoing are attained in theembodiments of the invention described in the accompanying descriptionand illustrated in the accompanying drawings, in which:

FIGURE 1 is an isometric view showing one form of pivoted blade lockdevice constructed pursuant to the invention as it is installed in atypical environment;

FIGURE 2 is a side elevation of the structure shown in FIGURE 1 withportions of the mechanism broken away to disclose the interior and withportions of the environmental structure broken away to reduce the sizeof the figure;

FIGURE 3 is a detail in elevation, the view being indicated by the line33 of FIGURE 2;

FIGURE 4 is a detail cross section, the plane of which is indicated bythe line 44 of FIGURE 2;

FIGURE 5 is a side elevation of a modified form of pivoted blade lockdevice;

FIGURE 6 is a cross section on a vertical longitudinal plane of afurther modified form of pivoted blade lock device in installedcondition, certain parts being omitted to reduce the size of the figure;

FIGURE 7 is a cross section, the plane of which is indicated by the line77 of FIGURE 6;

FIGURE 8 is a cross section, the plane of which is indicated by the line88 of FIGURE 6;

FIGURE 9 is a cross section on a vertical longitudinal plane through astill further modified form of the pivoted blade lock device shown ininstalled condition; and

FIGURE 10 is a cross section, the plane of which is indicated by theline Ill-10 of FIGURE 9.

As particularly shown in FIGURES 1-4 inclusive, a practical form of thepivoted blade lock device pursuant to the invention is designed forinstallation in connection with a door frame 6 including an upright doorjamb 7 having a transverse, vertical face 8 and connected by means of alintel 9 with an upright hinge post 11 of the door frame. Designed tooperate on the door frame and within the opening 12 defined thereby is adoor 13. Along one edge 14 the door is connected to the frame 6 by ap-3,3903% Patented July 2, 1968 "ice propriate hinges 16. These aredesigned to permit the door 13 to swing With respect to the door frameabout a vertical axis 17. Depending upon the installation, the doorpanel 13 can be mounted to swing on one side only of the door frame. Inthis case, the hinges are arranged so that the axis 17 is displaced toone side of the frame 6 and of the door 13. Another installation can bearranged by providing appropriate hinges permitting the door 13 to swingon both sides of the door frame. In this instance the axis 17 of thehinges, whether single or double hinges are used, can be considered tobe midway between the sides of the door frame substantially in themedian vertical plane of the door 13.

In the first instance, there is customarily provided a door stop (notshown) to limit the movement of the door in one direction, whereas inthe second instance no door stop is provided as the door is free toswing to either side of its center position and to swing through thecenter position when appropriately operated. Under both instances, thedoor 13 has an upright, planar face 19. In one, central position of thedoor in the door frame, the face 19 confronts the planar face 8 of thedoor frame, there being a slight clearance between the confronting faces8 and 19 to afford room for the arcuate movement of the door.

Despite the fact that the door always swings in a circular are about theaxis 17, it can be considered that the motion of the door edge when nearits center or closed location is substantially in a horizontal directionapproximately perpendicular or normal to the plane of the closed door 13and parallel to the plane of the faces 8 and 19. Since the door iscustomarily quite thin, the faces 8 and 19 need not be exactly planarnor parallel, and may be curved or divergent, but these geometricdesignations are close approximations and are used for clarity ofdescription.

Pursuant to the invention, there is mounted on the door 13 anappropriate latch unit 21. This is associated and interconnected with anactuator 22 not disclosed in detail since it is of a generallyrecognized, standard form mounted on and secured to the door 13.Usually, there is an actuating knob 23 on one side provided with a keymechanism 24. Usually, there is also a comparable actuating knob 23 onthe other side of the door panel. When either of the knobs is actuated,the mechanism transmits a corresponding motion to the latch unit 21.

The latch 'unit includes a housing 26 or frame of thin, generallyrectangular contour enclosing a central chamber 27 and joined to a latchplate 28 recessed within and substantially coplanar with the face 19 andsecured in position by fasteners 29. The plate 28 has a generallyrectangular latch opening 31 within and through which moves a blade 32mounted on a cross pin 33 serving as a pivot mounting with the axis ofthe pin 33 disposed in a horizontal direction. When the door is closed,the pin axis is parallel to the planes of the surfaces 8 and 19 and alsois parallel to the direction of motion of the door. The pin 33 ismounted in the housing 21 and in the blade at a location close to theplate 28 so that most of the blade swings through the latch opening 31and when in a retracted position substantially fills most of the opening31. In a projected position, the blade tipextends a desired distancefrom the surface 19, in practice approximately three-quarters of aninch.

In order that motion of the actuator 22 can be imparted to the blade 32,the blade is provided with a slot 38 within which fits an actuating pin39 mounted in the upcurved end of a bar 41. The bar is confined torectilinear translation by the walls of a passage 42 formed in thethickened interior end of the housing 21. The pin 39 operates within theslot 38 and the swinging of the blade is in accordance with the motionof the bar. The radial location of the pin 39 with respect to the pivotpin 33 is such that the desired excursion of the tip of the blade 32,such as three-quarters of an inch, is accomplished with a shorter motionof the bar 41 imparted to it by the knob 23 acting through anappropriate bar terminal 43, the actuator 22 and the housing 21 beingconnected by a similar interengagement 44-.

Conveniently, the housing is made in two halves secured together bythrough fastenings 46 and is installed by mortising the door, whereasthe actuator is installed in the usual way by a through bored hole.Various interconnections may be provided between the bar 41 and theactuator. They can be connected without substantial lost motion or therecan be lost motion permitting the bar to be moved inwardly While theactuator is stationary. If the actuator return springs (not shown) arealso effective on the bar 41, no other spring is needed, but in any casethe bar 41 can also have a biasing means such as a return coil spring 45held between the housing and a bar shoulder. The return spring iscompressed when the blade 32 is depressed into the housing by pressureon the exterior portion of the blade.

Pursuant to this invention, a strike device is provided to cooperatewith the blade 32. Recessed into the door frame 6 by appropriatemortising through the face 8 of the door jamb 7 is a strike unit 51.This includes a generally planar plate 52 set with its outer facesubstantially flush with the surface 8 and held in position by fasteners53. The strike plate is adjacent a strike recess 54 within the jamb 7,the recess being of sufficient width and depth readily to receive theprojected blade 32. The strike plate 52 is provided with a strikeopening 56 of generally rectangular configuration positionedsubstantially to confront the latch opening in the latch unit 21 so thatwhen the door is in central position or is closed, the blade 32 canreadily be received through the latch opening 56 with substantialclearance in a vertical direction if desired, but with substantially nolateral clearance in a horizontal direction.

The strike unit includes means for engaging and actuating the blade 32.The plate 52 on one side only, in the event the door is mounted to swingonly in one direction, but on both sides in the event the door isdesigned to swing in both directions, has an integral extension 58 orwing located in substantially horizontal alignment with the opening 56.The extension 58 has a cam edge 59 along one portion and has arelatively straight edge 61 along another portion, the edges 59 and 61merging in a smooth curved edge 62. The cam edge 59 merges smoothly withone of the side edges 63 of the strike plate.

The configuration of the cam edge 59 is such as to abut or engage asimilar cam edge 64 on the exposed portion of the blade 32. The edges 59and 64 are approximately at right angles. The configuration is such thatthe portion of the cam edge 59 farthest from the door jamb firstencounters the portion of the substantially radial cam edge 64 closestto the pivot pin 33. As the door swings with respect to the door frame,or as there is relative motion between the strike unit and the latchunit, particularly as the door approaches its closed positionsubstantially in a predetermined direction, the cam edge 59 bears uponthe cam edge 64 in a progressive fashion. The blade 32 is progressivelydepressed until the lowermost portion of the blade or that portionfarthest from the pivot pin 33 is substantially flush with the plate 28.The tip of the blade can then ride over the strike plate until the bladeis in alignment with the strike opening 56. Thereupon the springmechanism in the actuator, being effective through the bar 41, causesthe blade 32 quickly to swing through the openings 31 and 56, to spanthe gap 12, and to be positioned within the strike recess 54. The bladeis laterally confined between the sides of the opening 56, to index andhold the door in position with respect to the door frame.

FIGURE 1 includes projection lines 66 to indicate that for selectedincrements of the radial length of the blade 32 the cam surface 59 canbe appropriately contoured so as to afford any desired amount ofdepression of the blade as the door swings toward its closed position.Usually, substantially equal increments of latch blade motion areprovided for equal angular intervals of door closure. With thisarrangement, the vertical height of the cam surface 59 can besubstantial. Even though the cam surface is on a planar plate locatedapproximately in the direction of closure of the door substantiallynormal to the plane in which the blade 32 swings, there is neverthelessa favorable mechanical interengagement with approximately point contact.The blade 32 swings in regularly and easily and the door is closed andlatched with little effort. If the door is mounted to swing through theopening, then the extension 58 is duplicated by a mirror symmetricalwing or extension 67. Since the blade 32 is already symmetrical, noalternation need be made in it for either type of installation. Inpractice, some rounding of the contacting edges is preferred either onthe blade 32 or on the plate 52 or on both.

Under some circumstances, it is advisable to rovide a blade lock devicewhich is proof against tampering. A thin instrument such as a cardinserted into the opening 12 above the blade and then lowered will camagainst the blade surface 64 and will release the lock. To prevent this,there is provided in the form of device particularly shown in FIGURE 5 alatch unit housing 81 associated with a latch plate 82 slightly recessedin the face 83 of a door 8-: and secured by fasteners 35. The housing 81is associated with a standard lock actuating unit (not shown) connectedto operate a bar 87 to swing a latch blade 88 mounted on a pivot pin 89situated in the housing 81. The connection between the rectilinearlymovable bar 87 and the blade 88 is by means of a connecting pin 91operating in a slot 92. Thus when the bar 87 is translated, the blade 88is swung.

To cooperate with the latch unit, there is provided in the door jamb 93a strike plate 94 secured on the jamb face 96 by fasteners 97. The plate94 opposite the blade 88 has a strike opening effective to receiveprojecting portions of the blade and the door jamb also has a recess 98for that purpose.

The blade 88 does not have a continuous exposed edge, but rather iscontoured to afford a substantially radial carnming edge 99 merging witha circular are surface 361 and a rectilinear surface 102. This isarranged with the arcuate surface 101 to define a notch in the bladeedge 99. The location of the surfaces is such that the only portion ofthe blade exposed within the gap between the faces 83 and 96 when theblade is projected has a surface substantially circular about the pin 89as a center. With this arrangement, when any blade or card is moved inthe gap 100 either upwardly or downwardly, no substantial rotationalcomponent can be imparted to the blade. The blade is substantiallydeadlatchcd and cannot be reversed by vertical forces exerted upon theblade itself.

The cam edge 99 is not sufficiently extensive to swing the blade 88 forits full travel. The strike plate 94, therefore, is provided with anangularly extending wing 163 so that when the door 8:3 moves towardclosed position the leading point or nose 164 of the blade is cammedhorizontally and laterally against the inclined wing 103. The blade 88is thus swung into its retracted position and then springs out throughthe opening in the strike plate 94. This action is different from thatin the FIGURES 1-4 device. Therein all of the camming action to depressthe strike plate occurs along the radial cam edge in a generallyvertical direction, whereas in the FIGURE 5 device the carnming actionoccurs on the nose 164 of the blade and in a generally horizontaldirection. If the door 84 swings both ways through the opening of thejamb, there are extensions such as 103 on both sides of the plate 94.

Under some circumstances, the scrni-dcadlatch action of the FIGURE 5device may not be sutlicient and a full deadlatch arrangement isprovided. As shown in FIG- URES 6, 7 and 8, the swinging door 111 ismounted, as before, to cooperate with a door jamb 112. The door 111carries a latch housing 113 secured in position by a latch plate 114having fasteners 115 entering into the door material. The housing 113confines an actuating bar 116 to rectilinear translation. A projectingspring 117 at one end bears against a cross pin 118 spanning the sidesof the housing 113 and operating in a slot 119 in the bar 116. At theother end, the spring 117 bears against a cross pin 121 in the bar sothat the bar is projected toward the left in FIGURE 6. The casing andthe bar are both provided with interconnecting devices 122 and 123 to anactuator (not shown) in the usual fashion.

The forward end of the bar 116 is provided with an upturned end 124having an inclined slot 126 therein. A pin 127 operates in the slot andis mounted on a center blade 128 supported in the housing 113 by a pivotpin 129. Also pivoting around the pin 129 are deadlatch plates 131 and132 approximately coextensive with the blade 128. These have free motionwith respect to the blade 128 by reason of a lost motion connection.This includes slots 133 in both of the plates 131 and 132 whichcooperate with a cross pin 134 in the central blade 128. The deadlatchplates 131 and 132 adjacent their lower ends are each provided with aradial surface 136 adapted to abut the forked, straight end 137 of aleaf spring 138. A loop 139 at one end of the leaf spring is seatedwithin a correspondingly shaped portion of the housing 113 and isrecurved to provide a finger 141 resting against the side of the housingand holding the blade 128 in position approximately normal to thesurface 136.

With this relationship of the parts, any force exerted on the sideplates 131 and 132 tending to rock them inwardly of the housing 113quickly takes up the lost motion between the radial surfaces 136 and theforked end 137 of the spring so that the plates 131 and 132 arerestrained and cannot then be depressed. This affords an appropriatedeadlatch. However, if the blade 128 is itself forced inwardly, a camsurface 142 thereon bears against a downturned cam follower 143 at thecenter of the spring 138 and cams the leaf spring 138 downwardly out ofthe way, thus removing the bifurcated end 137 from the path of thesurfaces 136. This motion is permitted by movement of the pin 134 towardthe other end of the slots 133. When this occurs, all three of theplates 128, 131 and 132 can be depressed. When released, they springback to their projected position.

In this instance, the nature of the strike plate 146 on the door jamb112 is substantially the same as that shown 1 in FIGURE 5, extending onone side only of the jamb in the event the door panel swings in only onedirection, but being duplicated on the other side and extending inmirror symmetry therefrom in the event the door swings in bothdirections.

Under many circumstances, the friction between the nose of the latchblade 128 and the strike plate 146 is reduced by providing the blade 128with an antifriction roller 147 mounted on a radial pin 148 seated inthe central blade 128, there being appropriate notches 149 cut from theside plates 131 and 132 to afford adequate freedom of motion of theroller 147. Conveniently, the plates 131 and 132 can be joined or can bemade integral by a bridge over the center blade 128, as shown in FIGURE6.

A somewhat simplified version of the deadlatching arrangement isprovided as shown in FIGURES 9 and 10. A latch housing 151 is mounted ina swinging door 152 of the type previously disclosed, the housing beingsecured to a latch plate 153 appropriately fastened in place. Thehousing 151 confronts a strike plate 154 mounted in the face of the doorjamb 156 in asuitable fashion and has an extension wing 157 for a doorswinging only one way and provided with a symmetrical extension wing 158for a door swinging both ways.

The strike plate 154 has an opening 159 leading to a cavity 161 in thedoor jamb 156 designed to receive a swinging latch blade 162. This ismounted on a pin 163 supported in the housing 151 and extends through alatch blade opening 164 in the plate 153. The blade 162 is normallyurged to project by a coil spring 165 at one end seated in a recess 166within the housing 151 and at the other end seated in a recess 167 inthe blade 162. Also connected to the blade 162 is an actuating bar 168at its end 169 provided for interconnection with a standard operatingdevice interconnecting with projections 171 on the housing 151.

The bar 168 is confined to rectilinear translation relative to thehousing 151 and at its forward end carries a cross pin 172 designed tooperate in a straight, horizontal path. The pin 172 extends on oppositesides of the bar 168 and on both sides lies within recesses 173virtually inverted L-shaped in configuration. This affords a clearance174 in a horizontal direction for the pin 172, affords a shoulder 176adjacent the pin 172, and also provides a depending portion 177 beneaththe pin 172. The blade 162 cannot swing about the pin 163 when the pin172 is in the upper portion of the slot 173 adjacent the upper boundaryof that slot and the shoulder 176. This is because the blade 162 inrotating about the pin 163 tends to lift the shoulder 176 against thepin 172, but the pin 172 is constrained by the rectilinearly movable bar168 against any rising or lifting motion. Thus a force exerted along theouter edge 178 of the blade 162 is ineffective and the blade is held inits projected position. This is a fully deadlatched blade.

In order that the blade can swing inwardly upon contact with the strikeplate wings 157 or 158, the blade 162 is provided with a stepped bore181 extending tangentially to the pivot pin 163 and emerging from theblade at its nose 182. Projecting from the nose is a follower 183 oflarger diameter than a rod 184 lying within the stepped bore. A spring185 at one end bears against the follower 183 and at the other end bearsagainst a shoulder 186 in the stepped bore. The follower 1'83 and therod 184 are joined together with an enlarged portion 187 of the rodbearing within the smaller diameter of the stepped bore and having itsend adjacent the forward end of the bar 168.

When the follower 183 projects in its normal situation under the urgencyof the spring 185, it is slightly spaced from the end of the bar 168.When the follower contacts the wing 157, for example, of the strikeplate 154, the lateral force thereon is caused by the favorableangularities to drive the follower 183 into the stepped bore 181. Thisnot only compresses the spring 185, but the inner end of the rod 184bears against the adjacent forward edge of the bar 168 and cams the bar168 slightly to the right in FIGURE 9. That moves the pin 172 away fromthe shoulder 176 to occupy the upper right-hand portion of the slot 173.Further tangentially inward movement of the follower 183 is precluded.Either the bearing of the follower or the bearing of the nose 182 of theblade 162 against the strike plate wing 157 swings the blade inward- 1y.This can easily occur since the pin 172 is received in the dependingportion 177 of the slot 173 and the discrepancy between the circularmotion of the blade 162 and the rectilinear motion of the bar 168 isaccommodated.

When the force tending to depress the blade is removed, the spring 165urges the blade to project into the cavity 161 through the strike plateopening 159. The bar 168 is transmitted to its extreme left-handposition in FIGURE 9 by the normal spring mechanism in the actuator (notshown) which always urges the bar 168 to the left unless a superiorforce actuates it to the right. With this form of device, the door,although extremely thin, carries an effective, swinging blade latchdevice with a deadlatch feature, the door being effective to swing toone side only of the door frame or, if desired, to swing to 7 eitherside of the door frame and in either case to be firmly locked in itscenter location.

What is claimed is:

1. A pivoted blade lock device comprising a strike unit and a latch unithaving two vertical faces adapted to move substantially into and out ofconfronting relationship by motion relative to each other in apredetermined substantially horizontal direction parallel to said faces,said strike unit having a plate defining one of said vertical faces andhaving a strike opening therein, means on said plate horizontallyaligned with said strike opening and defining a first cam edge theactive portion of which has a slope inclined toward said strike opening;and said latch unit having a plate defining the other of saidvertical-faces and having a latch opening therein adapted to confrontsaid strike opening, a vertically disposed blade, and means for mountingsaid blade on said latch unit for swinging movement through said latchopening about a pivotal axis adjacent one end of said latch opening andextending in said predetermined horizontal direction when said faces arein said confronting relationship, said blade having a second cam edgeadapted to abut said first cam edge.

2. A pivoted blade lock device as in claim 1 in which said second camedge extends approximately radially of said axis.

3. A pivoted blade lock device as in claim It in which the part of saidactive portion of said first cam edge horizontally farthest from saidstrike opening abuts the part of said active portion of said second camedge radially closest to said axis.

4. A pivoted lade lock device comprising a latch unit including a platehaving a latch opening therein, a vertically disposed blade, means formounting said blade on said latch unit for swinging movement throughsaid latch opening about a pivotal axis adjacent one end of said latchopening and extending in a horizontal direction, said blade having a camedge extending approximately radially of said axis, and a strike unitincluding a plate having a strike opening therein adapted to receivesaid blade, and edge means on said plate adapted to abut said cam edgeradially closest to said axis when said latch unit and said strike unitare relatively far apart and progressively to abut said cam edgeradially farther and farther from said axis as said latch unit and saidstrike unit move relative to each other toward a position with saidstrike opening and said latch opening substantially in confrontingrelationship.

5. A pivoted blade lock device comprising a strike unit including asubstantially planar upright plate having a strike opening therein andhaving a side remote from said opening and defining cam edge with anactive portion inclined to the vertical, and a latch unit including ablade receivable in said strike opening and mounted to pivot about asubstantially horizontal axis and having an edge extending substantiallyradially of said axis and having different portions thereof engagingdifferent portions of said cam edge when said latch unit is moved in thedirection of said axis relative to said strike unit.

6. A pivoted blade lock device comprising a strike unit adapted to bemounted in an upright door frame, said strike unit includin" a strikeplate having an opening therein and having a side extension insubstantially horizontal alignment with said opening and comprising alatch unit adapted to be mounted in a door hinged to said door frame formovement substantially in a horizontal direction, said latch unitincluding a vertically disposed blade of substantially the same verticalextent as said opening, means 2" r mour. ng said blade near the upperend thereof to pivot on said latch unit about a horizontal axis insubstantial alignment with the upper part of said opening whereby saidblade can swing into and out of said opening, abutting means on saidblade and on said extension of said strike plate including a radial edgeon said blade and a marginal edge on said strike plate having contoursto engage each other with progressive points of contact as said blademoves over said strike plate to swing said blade about said horizontalaxis and in a vertical plane as said door and said door frame moverelative to each other substantially in a horizontal direction.

7. A pivoted blade lock device as in claim 6 and including meansconfined to reciprocation in said latch unit and engaging said blade forswinging said blade about said axis.

References Cited UNITED STATES PATENTS 111,995 2/1871 Vvarren 292-224429,948 6/1890 Page 292-224 452,777 5/1891 Eckert 292-225 464,47812/1891 Matthews 292-223 X 478,917 7/1892 Candee. 1,526,164 2/1925McCune 292-224 X 1,708,444 5/1929 Hampton 292-224 2,062,073 11/1936Tendler 292-223 X 2,534,693 12/1950 Adams 292-223 2,942,906 6/ 1960Gilpatrick 292-224 RICHARD E. MOORE, Primary Examiner.

1. A PIVOTED BLADE LOCK DEVICE COMPRISING A STRIKE UNIT AND A LATCH UNITHAVING TWO VERTICAL FACES ADAPTED TO MOVE SUBSTANTIALLY INTO AND OUT OFCONFRONTING RELATIONSHIP BY MOTION RELATIVE TO EACH OTHER IN APREDETERMINED SUBSTANTIALLY HORIZONTAL DIRECTION PARALLEL TO SAID FACES,SAID STRIKE UNIT HAVING A PLATE DEFINING ONE OF SAID VERTICAL FACES ANDHAVING A STRIKE OPENING THEREIN, MEANS ON SAID PLATE HORIZONTALLYALIGNED WITH SAID STRIKE OPENING AND DEFINING A FIRST CAM EDGE THEACTIVE PORTION OF WHICH HAS A SLOPE INCLINED TOWARD SAID STRIKE OPENING;AND SAID LATCH UNIT HAVING A PLATE DEFINING THE OTHER OF SAID VERTICALFACES AND HAVING A LATCH OPENING THEREIN ADAPTED TO CONFRONT SAID STRIKEOPENING, A VERTICALLY DISPOSED BLADE, AND MEANS FOR MOUNTING SAID BLADEON SAID LATCH UNIT FOR SWINGING MOVEMENT THROUGH SAID LATCH OPENINGABOUT A PIVOTAL AXIS ADJACENT ONE END OF SAID LATCH OPENING ANDEXTENDING IN SAID PREDETERMINED HORIZONTAL DIRECTION WHEN SAID FACES AREIN SAID CONFRONTING RELATIONSDHIP, SAID BLADE HAVING A SECOND CAM EDGEADAPTED TO ABUT SAID FIRST CAM EDGE.